FAU Police Chief Charles Lowe said that when his officers received arrived at the scene, the suspect pulled out a knife. He said shots were fired, and the suspect was struck.

The man was taken to Delray Medical Center in serious condition, but his name has not been released. It's not clear why he was on the roof or why he was making threats, or how many shots were fired.

"Officers (were) presented with what we believe was a threat, and they dealt with that threat," Boca Raton Police Chief Dan Alexander said.

The campus was never on lockdown and no one was in danger, school officials said.

Another threat took place at FAU in November, when the campus went on lockdown after a report of an armed man who pointed a gun to a student's head. No shots were fired and no one was hurt, and the lockdown was lifted a few hours after it was issued.

And just Thursday, authorities arrested a man after exchanging gunfire with him on the campus of Indian River State College in Fort Pierce.